The discovery of a huge canyon in Greenland Ice - Money.pl

id=”inContext_disabled”> 2013-08-29 19:42

id=”inContext_disabled”> [Photo: VinceHuang / CC / Flickr]

below the ice of Greenland lies canyon, comparable with parts of the Grand Canyon in the USA. It has at least 750 km long and in places up to 800 m deep and 10 km wide. The discovery is described in the latest issue of the magazine.

true shape of the surface of the Greenland ice sheet, scientists know comparing with each other, like a puzzle, the results collected over several decades by various methods. Some data provided NASA, other aircraft were acquired. However, information on the terrain, under armor, ice obtained with radar, the microwave frequency signals penetrate the ice and bounce off the current underlying rocks.

Jonathan Bamber of the Bristol School of Geographical Sciences (UK) and his colleagues, after an analysis of the data obtained image of the surface of Greenland, now covered with ice cover, the average thickness of more than 2 km.

As the researchers say, in the central part of the island to the north-Krance (culminating in a deep fjord connected to the Arctic Ocean) stretches for almost 750 km large, single canyon.

– time when using Google Street View, you can virtually walk through the many cities of the Earth, and when we digital maps showing the phenomena as diverse as the population density and distribution of happiness among the inhabitants of the earth – you would think that the whole landscape has long been well understood and illustrated by maps. But there is still a lot to discover – says the lead author of the study, Professor. Jonathan Bamber.

– Our study is important for a better understanding of the past Greenland. The ice cover in the region involved because the processes that cause the rise in sea level. This work can help us put the current changes in the broader context – adds Professor. David Vaughan of the British Antarctic Survey in Cambridge, the great EU project coordinator ice2sea , which aims to investigate the influence of glaciers on the sea level.

Powerful

before the canyon was developed Greenland glacier, which – according to the authors of the publication – there might be some 3.5 million years ago. – Before covered Greenland glacier was the beginning of the canyon at an altitude of a thousand meters above sea level It could swim the river and rain water. The subsequent development of the ice sheet could preserve the canyon. Later, the canyon could be exacerbated by the flow of water under the ice – explains prof. Jacek Jania, head of the Department of Geomorphology at the University of Silesia.

Even today canyon probably discharged into the ocean water, which melted the glacier from the heat penetrating the Earth’s crust. If the water did not drain and gathered with time could be built more Ice water tanks under pressure, acting as Grease reduces the friction between the ice and the rock surface. This would facilitate faster movement of glaciers to the sea and the detachment of the greater number of icebergs. Hitting the top of the displace sea water and mechanically increase the level of the ocean.

– However, if there is a drainage system, however, such as newly discovered canyon, the water can easily drain away, the force of friction between the glacier and the ground is maintained glacier hike slows and icebergs end up in the ocean much less – explains prof. Jania.

– This finding may be of paramount importance for the consideration of future sea-level rise in the world. Who knows if there is good news for residents of low-lying areas of the Earth – adds the expert from the University of Silesia.

professor recalls that at the beginning of this century Greenland’s glaciers that flow into the sea, clearly accelerated their movement and began to produce large quantities of icebergs, especially in the southern part of the island and within the Petermann glacier – where the ends of the newly discovered canyon .

– initially high rate of movement of glaciers slowed down since around 2008, though still high melting ice. Also slightly decreased the rate of calving, or detachment from them fragments that fall into the sea. You can now speculate that the current in Greenland continental glacier water is actually rapidly removed, thanks to an effective drainage system. This makes it difficult journey faster glaciers. Now we know how this mechanism can decide – said prof. Jania.

– Identify the canyon to the conclusion why in Greenland – at least in one part, there is a large subglacial lakes – such as the Antarctic – added the scientist.